Speaking at the JP Morgan technology conference today, AT&T CEO Ralph de la Vega has once again expressed confidence in Windows Phone, noting Nokia Lumia 900 sales have exceeded expectations, and that he expected Windows Phone sales would get a further boost from Windows 8, which would unify the UI of desktops, tablets and phones.

He said:

I am really pleased with what I am seeing out of Microsoft and Nokia coming out with their first product. The operating system works really well. It is simple, it is easy to use, it is intuitive.

The reception to the Lumia launch has actually exceeded our expectations. So we think there is a very good chance that Microsoft will have a very good OS that will be right in there with iOS and Android.

When they come out with Windows 8 in the fourth quarter, I think it will actually add to the value that that OS brings to the marketplace, in that that will be the first time that you can truly have a similar experience on your PC, on your tablet, and on your smartphone from soft Microsoft. From what I have seen and the previews that I have been given, I think it is going to be exceptionally good. I am very upbeat in what they are bringing to the market.

Windows Phone has made unexpected market share gains in recent months, suggesting we may all be surprised at the smartphone situation at the end of the year.